The present invention relates to a drain cleaning machine, and more particularly to a release assembly for removing the rotatable drum from the machine without tools.
Conventional drum type drain cleaning machines typically include a frame structure supporting a rotatable snake drum and a drive motor arrangement for rotating the drum. The frame structure also supports a snake feeding arrangement by which the snake or cable is axially displaced relative to the rotating drum during use of the machine. The snake coiled within the rotatable drum is displaced by the feeding arrangement and inserted into a pipe or drain to be cleaned. Rotation of the drum rotates the snake to achieve such cleaning.
The rotatable drum in known drain cleaning machines may typically be removed from the support frame and drive arrangement to facilitate replacement of the drum with one containing a snake having a different diameter and to make the separate components more mobile. Disadvantageously, conventional removable drums require tools to disassemble the rotatable drum from the support frame. This, of course, requires access to the proper tools and is also somewhat time consuming for the operator. Other known disassembly arrangements require a groove cut in a shaft which mounts the rotatable drum. The groove is located between the rotatable drum and the support frame to receive a spring loaded pin which rides within the groove. The pin is retracted to disassemble the rotatable drum from the support frame. By its location, the groove reduces the strength of the shaft in a weight bearing segment. Friction between the groove and the single pin may also eventually require the repair or replacement of the disassembly arrangement. Further, the pin must be manually retracted to both install and remove the rotatable drum.
Accordingly, it is desirable to provide a rotatable drum release assembly which provides an effective release without the necessity of tools and which locates shaft grooves in a position to minimize their load bearing effect on the shaft. It is further desirable to provide a rotatable drum release assembly that need not be manually actuated to assemble the rotatable drum to the support frame.
The drum release assembly according to the present invention provides a latch which engages an inner diameter of a plate spaced away from a rotary drum to lock and unlock the rotary drum to a drain cleaning machine. The drum shaft extends from a sleeve in a cantilevered manner and as the latch engages the plate, no shaft grooves are located in the shaft. Localized weakening of the shaft is thereby prevented.
Each latch is telescopically mounted within a latch sleeve which forms a substantially T-shaped arrangement with the shaft sleeve. Biasing members within each latch sleeve bias a latch outward. The latch sleeves extend for a linear distance less than the diameter of the inner opening of plate while the latches extend from the latch sleeves a total linear distance just greater than the diameter of the inner opening.
To mount the drum, the drum shaft is pushed into the sleeve. Contact between a wedge shaped face of the latch and inner opening of the plate forces the latches to be retracted into the latch sleeves. Once the inner opening of the plate passes the latches, the biasing members drive the latches outward. The drum is thereby rotatably locked in place by the interaction between the extended latches and the inner opening of the plate.
Lifting an actuating handle engages cam surfaces with the latches to simultaneously retract the latches into the latch sleeves. Once the latches are linearly retracted to a distance less than the inner opening of the plate, the drum is released.
The present invention therefore provides a rotatable drum release assembly which provides an effective release without the necessity of tools and which eliminates shaft grooves. The present invention further provides a rotatable drum release assembly that need not be manually actuated to assemble the rotatable drum to the support frame.